In an evaluation of a method for the determination of fluorene in seawater,a synthetic sample of seawater was spiked with 50 ng ml of fluorene. Ten replicate determination of the fluorene concentration in the sample had amean of 49.5 ng ml with a standard deviation of 1.5 ng ml .
Calculate 95% confidence limits of the mean. Is the spiked value of 50 ng ml within 95% confidance limits?